The present invention is a method for manufacturing a rubber composition that contains: a rubber component (A) comprising at least one type of rubber selected from among natural rubbers and synthetic diene rubbers; a filler containing an inorganic filler (B); and a silane coupling agent (C) comprising a compound that has a mercapto group. Said manufacturing method is characterized in that: said rubber composition is kneaded in multiple stages; after the rubber component (A), some or all of the inorganic filler (B), and some or all of the silane coupling agent (C) are kneaded together in the first kneading stage, at least one compound selected from among acidic compounds (D) and basic compounds (E) is added in the first stage or a subsequent kneading stage; and the maximum temperature of the rubber composition during the final kneading stage is 60-120 DEG C. Without decreasing the workability of the unvulcanized rubber composition, this method for manufacturing a rubber composition is capable of further increasing the coupling activity of the silane coupling agent, obtaining a very low-heat-generating rubber composition.